{
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\begin{tabular}{l*{4}{c}}
\toprule
                    &\multicolumn{1}{c}{\emph{E. coli} present}&\multicolumn{1}{c}{TC present}&\multicolumn{1}{c}{\emph{E. coli} (MPN)}&\multicolumn{1}{c}{TC (MPN)}\\
                    &\multicolumn{1}{c}{(1)}   &\multicolumn{1}{c}{(2)}   &\multicolumn{1}{c}{(3)}   &\multicolumn{1}{c}{(4)}   \\
\midrule
Caretaker           &       -0.04   &       -0.07   &       -0.06   &       -0.53   \\
                    &      (0.04)   &      (0.15)   &      (0.06)   &      (0.41)   \\
Flame               &        0.07   &       -0.03   &        0.30   &       -0.06   \\
                    &      (0.08)   &      (0.16)   &      (0.32)   &      (0.58)   \\
Weak chlorine       &        0.04   &        0.02   &        0.18   &        0.07   \\
                    &      (0.07)   &      (0.15)   &      (0.18)   &      (0.50)   \\
\midrule
Observations        &          89   &          89   &          89   &          89   \\
\bottomrule
\end{tabular}
}
